There should be a minimized icon in the system tray. Right mouse click on it and choose 'close window' to end the uninstallation.Launch task manager and end the process setup.exe, if it is still running.

Verify the following components have been removed from the APM web and APM application servers:

On APM Web server: launch IIS manager, and remove the 'APMWebSite'

From Control Panel\Programs\Programs and Features, right mouse click on the component CommonAdministrationforServiceManagement and uninstall